Optical imaging system with encapsulation and tether

ABSTRACT

A tethered imaging camera encapsulated in a shell lens element of such camera enables viewing from inside and imaging of a biological organ in/from a variety of directions. A portion of camera&#39;s optical system together with light source(s) and optical detector mutually cooperated by housing structure inside the shell are moveable/re-orientable within the shell to vary a desired view of the object space without interruption of imaging process. A tether carries electrical but not optical signals to and from the camera and controllable traction cords to move the camera, and a hand-control unit and/or electronic circuitry configured to operate the camera and power its movements. Method(s) of using optical, optoelectronic, and optoelectromechanical sub-systems of the camera.

CROSS-REFERENCE TO RELATED APPLICATIONS

This US Patent Application is a continuation of the International PatentApplication No. PCT/US2021/027212 filed on Apr. 14, 2021 and nowpublished as WO 2022/220816. This US Patent Application is also acontinuation of the pending U.S. patent application Ser. No. 18/124,172,which in turn is a continuation of the International Patent ApplicationNo. PCT/US2021/027212 filed on Apr. 14, 2021 and now published as WO2022/220816. The entire disclosure of each of the above-identifiedapplications is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to imaging of inside of biological organsand, more particularly, to an imaging system one portion of which isjudiciously encapsulated by another portion and is configured to berotatable within such other encapsulating portion with the use ofmechanical members passed through an aperture defined by theencapsulating portion.

RELATED ART

In order to examine specific bodily organs such as the esophagus,stomach or small intestine (gastrointestinal tract), related artcurrently utilizes endoscopes—elongated, flexible or rigid, instrumentsconfigured for imaging internal bodily organs. The structure (and, inparticular, the size and shape) of such instruments (about 10 mm indiameter by about 1,100 mm in length) require that examination procedurebe formatted in a very specific way: a patient must be at a minimumunperturbed and, preferably, sedated during the procedure. An instrumentof such a large size has to be advanced from the mouth, via the pharynxto the esophagus, stomach and beyond by pushing the device forwardswhile viewing the path along which the device is being moved. At least aportion of such device includes a rigid or flexible long insertionsheath (typically, of about 10 mm in diameter) carrying various wires,optical channels, other hardware components in its hollow and protectingthese contents from the environment.

Furthermore, a physician needs to somewhat forcibly advance theendoscope along the digestive tract; the device cannot be simplyswallowed and advanced without applying this force. The operation of aso-conventionally-structured scope is then inevitably associated withphysical rotation or deviation or bending of, for example, the distalend of the sheath from or with respect to its original position. That,in turn, leads to physical impact between the probe and the physicaltissue, thereby causing trauma to the bodily cavity. Even to toleratesuch a procedure—let alone to have the examination go smoothly andwithout disruptions, to collect required data—a patient typically has tobe sedated, which increases the risk of a procedure by blunting theprotective physiological reflexes. Traditional endoscopes achieveviewing in a plurality of directions by moving/bending the tips of theendoscopes to direct imaging cameras, which can result in trauma to thelining of an organ with which the tip interacts. Moreover, retroflexedviews through such traditional endoscopes are at least partiallyobscured by the very sheath of the device.

While wireless, stand-alone swallowable imaging probes encapsulated in asealed capsule-like housing could be considered as alternatives toprovide images from within the body, such as gastrointestinal tract, theimaging process is recognized to be hampered by poor image resolutiondue to small optics and a small image sensor used, with images thatusually have to be first stored and viewed only after the procedure oncedownloaded. A skilled artisan readily recognizes that, even if awireless capsulated camera could be formatted to transmit live video, itwould not be practical to implement control of the camera at thediscretion of the user because the direction, position, and movement ofthe wireless capsule is determined by gravity, changes in body position,muscular movements of gastrointestinal organ or surrounding organs—mostof which parameters vary with time and from patient to patient. The lackof control of imaging direction, for example, detrimentally affects theimaging procedure as it results in incomplete viewing of an organ cavity(such as the stomach, for example), thereby leading to missed lesionsand eventual misdiagnosis. Even if a lesion or target is brieflyobserved, a free-falling capsule prevents such an area to be imaged asecond time or repeatedly, if it is required to reconfirm the collectedinformation or provide a detailed close-up view. Indeed, a physician mayrequire a side view of an ulcer in a stomach to observe its margin inorder to assess for signs of neoplastic growth such as raised margins;or may wish to use to use additional monochromatic wavelengths ratherthan white light, to increase contrast of imaging; or use imagingmethods including fluorescence, auto fluorescence, or second- orthird-harmonic generation techniques to garner structural or metabolicinformation about various tissues. The need for repeated views with thesame or different imaging modalities and from different angles canprovide valuable diagnostic information.

When examining an organ such as the stomach, it is important torepeatably view the entire organ so as not to miss any lesion. Theoperator's ability to control the rotational movement as well asmovement along the altitude as well as the conscious patient's abilityto change body positions will allow a completely spherical view to beacquired. A completely spherical view is not ordinarily possible with atraditionally-configured sheathed scope-like probe tube (let alone thecomplexities involved in carrying out the corresponding imagingprocedure), while both the wide-angle and repeatable imaging processcannot be achieved with a stand-alone encapsulated camera.Currently-available imaging methodologies, therefore, fall short ofsatisfying the specific needs of imaging specific bodily organs such asthe esophagus, stomach or small intestine (gastrointestinal tract) atleast as far as versatility of the imaging and simplicity of the use areconcerned.

SUMMARY

Implementations of the idea of the invention address methods andapparatus for a tethered and encapsulated optoelectronic imaging systemstructured to view and image—in a repeatable fashion, if required—atarget object space in a variety of directions from inside biologicalorgans (such as, for example, the esophagus, stomach or intestines) orfrom inside inanimate objects or space. A portion of the optical systeminside the encapsulating housing or shell is structured to bejudiciously repositionable and can be oriented in a variety ofdirections while the shell—with respect to the considered portion of theoptical imaging system itself—remains fixed, thereby allowing the userto obtain a desired view without moving or repositioning the overalltethered system. (And yet, the repositioning of the overall tetheredsystem can be carried out by manipulating the tether, as discussedbelow.) A portion of the overall imaging camera inside the encapsulatinghousing shell contains lens elements, an image sensor or opticaldetector, some illumination sources, and associated electronics asdescribed, all held in a compact housing mechanical structure, and thuscan be viewed as an optoelectromechanical system. This camera housingstructure is configured in such a way as to be able to move inside theencapsulating shell, as desired by the user, and without anyinterruption of the imaging process. The narrow, flexible tether(configured such as to facilitate the swallowing of the system by apatient) is affixed to the capsule-like housing and not only carrieswiring needed to power the imaging camera and collect and transfer theimage data, but also the cords or strings configured to affect thedesired movement of a portion of the camera inside the capsule. Notably,in advantageous contradistinction with sheathed portions ofconventionally-structured endoscopes (laparoscopes, or otherconventional imaging probes), the tether of an embodiment of theinvention does not contain (that is, is devoid of, or lacks) any opticalchannel configured to transmit light from one end of the tether toanother. Depending on the specifics of the particular implementation,the shell encapsulating the optical system inside the volume of theshell may be configured as a part of the optical imaging train that isrequired to be present for forming an optical image of the target objectspace of operationally-satisfactory quality, thereby causing the shellto be viewed and operated as a lens element itself. In such a specificcase, as will be readily appreciated by a skilled person, one portion ofthe optical imaging train is structured to move inside another portionof the optical imaging train.

Embodiments of the invention provide an optical imaging system thatincludes at least a first optical element dimensioned as asubstantially-spherical shell having a shell axis and an optical lensthat has an optical axis and a front lens element, the front lenselement having an apex at the optical axis and facing the first lenselement. Here, the optical lens is mounted within the first opticalelement such as to be rotatable about an axis of rotation at a rotationangle that is defined between the shell axis and the optical axis andthat can be of each and every value within a range from about −90° toabout +90° in a chosen plane containing both the shell axis and theoptical axis. When a holder structure, dimensioned to hold elements ofthe optical lens is fixed spatial orientation with respect to oneanother, is added to the optical imaging system, the imaging system mayinclude at least one source of light affixed to the holder structureand/or an optical detector affixed to the holder structure. (In thiscase, the combination of the holder structure, the at least one sourceof light, and the optical detector are configured to be at leastpartially enclosed within the first lens element and rotatablesynchronously with the optical lens within the first optical elementabout the axis of rotation.) In at least one case, the optical imagingsystem includes a tether that is structured to include anelectrically-conducting member electrically-connecting one or more ofthe at least one source of light and the optical detector with an end ofthe tether distal to the first lens element and, at the same time, notcontain any optical member transmitting light along the tether.Optionally but preferably, the optical imaging system includes atraction string within the tether (with a proximal end of the tractionstring connected to the holder structure to effectuate a rotation of theoptical lens about the axis of rotation when repositioned along thetether). Preferably but optionally, the electrically-conducting memberis positioned within the first optical element to form a spatial loopabout an axle defining the axis of rotation and supporting the holderstructure at a stand element that maintains its orientation with respectto the first optical element regardless of the rotation angle. Theoptical imaging system may be structured in such a way that, whenrotation of the optical lens is carried out within the first lenselement, the apex of a front lens element of the optical lens remainssubstantially equidistant from the substantially-spherical shellregardless of a value of the rotation angle within the range ofrotation; and/or be structured such as to have a constant field of viewregardless of the rotation angle within this range. In one specificcase, each of the two lens elements of the optical lens that are closestto the substantially-spherical shell is shaped as an optical meniscus.In at least one implementation, the optical imaging system is configuredto dynamically image an object space within a linear angle of at least350 degrees by scanning such angle with the optical lens having asemi-angular FOV of more than 40 degrees while, at the same time,maintaining an optical surface of the optical imaging system that isclosest to the object space in a substantially unchanged orientation andposition with respect to the object space.

Embodiments of the invention additionally provide an imaging camera thatincludes an optical system defined by a first lens element and anoptical lens, an optical mount maintaining mutual orientations of lenselements of the optical lens with respect to one another; at least onesource of light cooperated with the optical lens in a spatially-fixedorientation with the use of the optical mount, and an optical detectorjuxtaposed with the optical mount to acquire light from an object spacethrough the first lens element and through the optical lens to form anoptical image of the object space. In the provided configuration, thecombination of the optical lens, the optical mount, the at least onesource of light, and the optical detector are encased by the first lenselement and configured to be rotatable within the first lens elementabout an axle of the optical mount. In at least one specific case, theimaging camera additionally includes an electrically-conducting memberdrawn through an aperture defined in the first lens element into avolume encased by the first lens element and connected to at least oneof the at least one source of light and the optical detector; and/or astring drawn through an aperture (defined in the first lens element)into a volume (that is encased by the first lens element) and connectedto the optical mount such that repositioning of the string along alength of the string causes the optical lens rotate within the firstoptical element about an axle such that a pre-determined point at theoptical lens remain substantially equidistant from the first lenselement regardless of an angle of rotation of the optical lens.

Embodiments of the invention also provide a method for imaging an objectwith an optical system comprising a first lens element having a firstaxis and an optical lens having a second axis. The method includes thesteps of rotating the optical lens within a volume defined by the firstlens element about an axis of rotation located within the volume; ateach angle of so rotating, acquiring light from the object through theoptical system with an optical detector positioned within the volume;and transferring a signal representing a spatial distribution of saidlight from inside the volume lens element to outside of the volume. (Inat least one specific case, the step of transferring a signalrepresenting a spatial distribution of the light may includetransferring such signal along the tether that is devoid of any opticalelement, while a distal end of the tether being attached to a componentcontained within the volume.)

In at least one implementation of the method, at least one of thefollowing conditions is satisfied: (a) the first lens element encases atleast a portion of the optical lens, and further comprising irradiatingan object with illuminating light delivered from a source of lightthrough only the first lens element, and (b) the process of acquiringincludes acquiring the light from the object through both the first lenselement and the optical lens; additionally, the process of transferringincludes transmitting an electrical signal and is devoid of transmittingan optical signal. Additionally or alternatively, and in at least oneimplementation, the process of rotating may include rotating the opticallens at a latitude angle of rotation while maintaining a distance (thatseparates a front lens element of the optical lens from the first lenselement) substantially constant for every latitude angle of rotationchosen at least within a range from about +90° to about −90° as measuredbetween the first axis and the second axis in a plane containing boththe first axis and the second axis. Additionally or in the alternative,and in at least one implementation of the method, the method may includea step of rotating the first lens element about the first axis by anazimuthal angle of rotation. (In one specific instance case, and whenthe optical system has a field-of-view with a semi-angle of at least80°, an aggregate solid viewing angle subtended by the optical system inthe object space by the rotation of the optical lens about the axis ofrotation and by the rotation of the first lens element about the firstaxis by 360° is at least 3π steradian.) Notably, the step of rotatingthe first lens element about the first axis may include twisting atether that is drawn through an opening in the first lens element toconnect contents of the volume with a point outside the first lenselement, while the tether lacks any optical channel connecting first andsecond points along a length of the tether.

In at least one specific implementation of the method, the first lenselement is dimensioned as a substantially-spherical shell having anaperture subtending a solid angle not exceeding 0.6π steradian as viewedfrom a center of curvature of a surface of the first lens element, whilethe process of transferring a signal representing a spatial distributionof light includes transferring an electrical signal through suchaperture in the first lens element. In at least one specificimplementation, the distance separating the front lens element of theoptical lens from the first lens element is maintained constant duringthe process of rotating the optical lens within the volume while, at theat the same time, the method is devoid of (does not include) a step ofrepositioning the axis of rotation within the volume. In at least oneimplementation, the process of imaging includes imaging a target portionof an esophagus, while the method additionally includes a step ofswallowing the optical system by a patient. (Here, the first lenselement is structured as a substantially-spherical shell having anaperture therein dimensioned to provide access to the volume, and suchaperture is substantially fluidly-impenetrably sealed with astress-relief seal.)

In at least one implementation, the step of acquiring light from theobject through the optical system includes acquiring such light througha sequence of three meniscus lens elements and/or acquiring such lightthrough a sequence of two lens elements, each having a correspondingpositive optical power and/or acquiring such light through a stopaperture that is separated from the object by a first optical groupincluding three lens elements and from an image plane by a secondoptical group that includes two lens elements. The step of acquiringincludes transmitting the light through a lenslet from the first opticalgroup and through a lenslet from the second optical group, such lensletshaving respective optical powers of opposite signs.) Alternatively or inaddition, every lens element from the first optical group has acorresponding optical power with a first sign, and every lens elementfrom the second optical group has a corresponding optical power with asecond sign, the first sign being opposite to the second sign.

In implementing the method, the optical system may be configured to havea FOV with a semi-angle exceeding 80°, while an aggregate, overall FOVthat the optical system covers in object space as a result of rotatingthe optical lens has a semi-angle of at least 170° with respect to thefirst axis. Alternatively or in addition, the method may compriserepositioning the object with respect of the optical system.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood by referring to thefollowing Detailed Description of Specific Embodiments in conjunctionwith the not-to scale Drawings, of which:

FIG. 1 provides a schematic perspective view of a portion of anembodiment of the invention.

FIG. 2 is a schematic perspective view of a portion of a relatedembodiment of the invention.

FIG. 3 provides an illustration of an implementation of a train of anoptical system of the imaging camera of an embodiment of the invention,configured to image a portion of the object space covered by thecorresponding field of view (FOV).

FIG. 4 provides description of transverse ray aberrations during theoptical imaging in the FOV through the optical system of FIG. 3 .

FIGS. 5, 6, and 7 respectively illustrate field curves, distortioncharacteristics, and the spot diagrams associated with the practical useof the embodiment of FIG. 3 during imaging of the object space in thecorresponding FOV.

FIG. 8 presents the curves of the modulated transfer function (versusimaging field) for the embodiment of FIG. 3 .

FIGS. 9A, 9B illustrate schematically viewing of a bodily organ with theencapsulated embodiment of the invention depending on the angularposition of a portion of the optical system of the imaging camera.

FIGS. 10A, 10B illustrate, in side views, an embodiment of a portion ofthe imaging camera schematically showing at least portions oftilt-driving cords/strings and electrical cables/members/wires insidethe housing shell. The tilt motion is driven by two lateral cords anddampened by a third cord. FIG. 10A: a side view showing ‘posts’; FIG.10B: a front view showing the center cord.

FIG. 11 provides a perspective a view of the embodiment corresponding toFIGS. 10A, 10B but without the outer housing shell to show positions ofcords, electrical wires and base plate.

FIG. 12 is a schematic diagram of a hand-held remote controller equippedwith a motor. The optionally present electronic circuitry and/ormicrocontroller configured to govern and operationally-cooperated withoptoelectronic components and/or subsystems of the embodiment of FIGS.10A, 10B are not shown for simplicity of illustration.

FIG. 13 provides a schematic of an example of a control panel of thehand-held remote controller.

FIG. 14 illustrates schematically a cross-section of a tether withelectrically-conducting members and low-friction tubes withcords/strings for traction drawn through the tether.

FIGS. 15A, 15B illustrate, in side views, a related embodiment of thesystem of the invention schematically showing at least portions oftilt-driving cords/strings and electrical cables/members/wires insidethe housing shell, as configured in this embodiment. The tilt motion isdriven by two lateral cords/strings attached to an outside surface ofthe housing of the lens. A third, dampening cord/string, is optional andis not shown. FIG. 15A: a side view showing ‘posts’ and both of the tiltcords; FIG. 15B: a front view showing only one of the cords.

FIG. 16 provides a perspective a view of the embodiment corresponding toFIGS. 15A, 15B but without the outer housing shell to more clearlyillustrate positions of cords, electrical wires and base plate.

FIG. 17 contains a schematic diagram of a hand-held remote controllerequipped with a motor, configured for use with the embodiment of FIGS.15A, 15B, 16 . The optionally present electronic circuitry and/ormicrocontroller configured to govern and operationally-cooperated withoptoelectronic components and/or subsystems of the embodiment of FIGS.10A, 10B are not shown for simplicity of illustration.

FIG. 18 illustrates schematically a cross-section of an embodiment of atether with electrically-conducting members and spiral coils containingcords/strings for traction drawn through the tether, configured with theuse of the embodiments of FIGS. 15A through 17 .

FIGS. 19A, 19B schematically illustrate yet another related embodiment,in which at least one of the electrical members/wires (connecting theoptoelectronic system of the camera with an outside, external point anddrawn through the tether) is directed laterally to form a spiral loopabout the axle of rotation of the camera before passing throughcorresponding hole(s) ion the base plate and entering the tether. Thepresence of the spiral loop(s) facilitates the tilt of the camerarepeatedly without breaking the electrical wires. The loops may beformed on one of both axels present in the embodiment.

FIGS. 20A, 20B illustrate is a simplified cross-section views anembodiment of the imaging camera of the invention in two positions. FIG.20A: nominal mutual orientation between the outer lens element and aportion of the camera enclosed by the outer lens element. FIG. 20B: theportion of the camera enclosed by the outer lens element is rotated at apredetermined angle B with respect to the outer lens element.

Generally, the sizes and relative scales of elements in Drawings may beset to be different from actual ones to appropriately facilitatesimplicity, clarity, and understanding of the Drawings. For the samereason, not all elements present in one Drawing may necessarily be shownin another.

DETAILED DESCRIPTION

In accordance with preferred embodiments of the present invention,methods and apparatus are disclosed for a camera structured as atethered capsule and configured for imaging the inside(s) of hollowbiological organs.

The much smaller dimensions of a tethered capsule (a sphere-like body ofabout 10 mm in diameter with a slim, flexible tether of about 3 mm of across-sectional extent) not only allows the examination to be toleratedwithout sedation, but requires the patient to be awake and cooperate byswallowing the capsule, to help to advance the capsule from the mouth tothe stomach or the small intestine. Indeed, the size and flexibility ofthe utilized tether makes it practically impossible to advance thecapsule into a bodily organ by force.

However, once swallowed, the variety of directions a tethered capsulecan view is limited. The advantage of a capsule with operator-directedrobotic movement of the camera(s) inside the capsule is to enable aplurality of views without requiring the capsule itself to beredirected. The tethered capsule, however, enables viewing of an organor inanimate space that are beyond the capabilities of a wirelesscapsule with stationary cameras. The viewing ability of such a anembodiment approaches, indeed surpasses that of a traditional endoscope;its small volume and flexibility not only allows an organ to be viewedwithout sedation and with greater safety, but allows variable directionsof views to be obtained, without bending or changing the shape and/orposition of the embodiment.

By confining movements of a portion of the optical imaging system withinthe outer shell or capsule of the overall camera, trauma to the liningof an organ during a viewing process (something that often occurs duringtraditional endoscopy when the tip of the endoscope is redirected tochange the angle of view) is avoided. Moreover, retroflexed views duringtraditional endoscopy are partially obstructed by the insertion tubes ofendoscopes (about 10 mm in diameter), whereas the view obstructed by aslim tether will be negligible and easily compensated by movements ofthe organ, space or organ, allowing a completely spherical view to beobtained. In an inanimate space, such a tethered capsule withrobotic-eye camera(s) allows viewing to be obtained in multipledirections through narrow orifices and in small areas where atraditional borescope does not have the room to flex its distal end.

The tethered capsule with a portion of the optical system of theinvention moveable inside the capsule provides the versatility ofobserving the object space in different directions without requiring thecapsule itself to be oriented in different directions. Theimplementation of the proposed embodiment achieves the change of viewingdirections, comparable to that provided by an endoscope, while notreorienting the orientation of the capsule in the object space, but bymovement of the optical lens inside the capsule. The tetheredencapsulated implementation of the idea of the invention, therefore,provides the viewing coverage comparable and/or exceeding that of anendoscope while remaining at a fraction of the endoscope size, enablingthe viewing procedures to be performed without sedation and with greatersafety.

Overview of an Encapsulated System

In accordance with an idea of the invention, with reference to FIG. 1that provides a general schematic view of one embodiment, a system 100is structured as a tethered (104) optoelectronic system 110 (configuredas at least a portion of an imaging camera and containing at least anoptical lens 114 in an optical lens holder structure 118). A The imagingcamera 110 is held by camera stands 122 merging to a supporting baseplate 122A inside an optically-transparent housing shell or capsule 120such as to remain moveable within the shell at least about an axis ofrotation (which is defined with respect to the stands 122 and/or axle(s)of rotation which may be connecting the stands 122 with the holder 118,and which may be represented by the angular coordinate denoted as“altitude”, and which in FIG. 1 corresponds to the Y-axis of the localsystem of coordinates). The holder 118 of the optical lens 114 inconjunction with at least the supporting stands 122 and the supportingbase plate 122A may be considered and interchangeably referred to as acamera housing structure. The optoelectronic and mechanical componentsof the imaging camera of the embodiment are operationally and physicallyconnected with a point outside the shell 120 and at a distal point ofthe tether 104 at least with electrically-conducting member(s) 124 andmechanical cords or strings 128 passing through the tether as discussedelsewhere in this disclosure. Notably, the camera housing structure isconfigured within the shell 120.

The capsule/shell 120 is smooth-surfaced, rounded at least at itsproximal and distal ends 120A, 120B to allow easy swallowing of thecapsule 120 by a human and removal of the shell with its contents fromthe body with the use of the tether 104. Nominally, the capsule 120 isspherical in shape. The size and dimensions (of about 10 mm diameter) ofthe shell 120 facilitate the use of muscles of swallowing wherebyperistalsis is used to advance the swallowed capsule 120 along the lumenof the esophagus and enter the stomach (similarly to how swallowed foodreaches the stomach). In practical use of the embodiment 100,peristalsis can be used to advance the embodiment beyond the stomach orin another part of the body entered through a natural orifice or stoma.A skilled artisan will readily appreciate that a much smaller capsule(e.g. the one with less than 3 mm diametrical dimension) cannot be soeasily swallowed and advanced through the esophagus; furthermore, atsuch small a size, the internal to the housing shell optics has to be sosmall as, when practically implemented, not be able to providehigh-resolution images—unlike a system 100 sized to containing a largerimaging sensor (optical detector) as part of the camera 110.

At least the portion of the outer casing 120 of the embodiment 100,through which imaging of the target object space is carried out, issubstantially spherical, optically-transparent and of optical quality asunderstood by a skilled artisan and preferably of uniform thickness, andwatertight (fluidly sealed), thereby allowing the optical images of anobject space outside the shell 120 to be captured clearly and withoutdistortion through and with the functional, optical-imaging-wiseparticipation of such outer shell 120. It is understood, therefore, thatin an optional but preferred implementation the optical system of theimaging camera of the invention includes and requires the presence ofthe shell 120 that is dimensioned as a lens element having a non-zerooptical power. In this case, understandably, the camera housingstructure is configured within a non-zero optical power lens elementforming a portion of the optical system of the very camera that suchhousing structure supports, and a portion of the imaging camera isencapsulated in such lens element forming a portion of the opticalsystem of the very imaging camera, and electrical and mechanical members124, 128 in this case are passing into the tether 104 through anaperture defined in such lens element.

At this point, defining the meanings of at least several terms would bebeneficial. To this end, for the purposes of this disclosure andappended claims—and unless specifically defined otherwise, a “sphericalshell” is defined as and considered to be a region of a ball between twoconcentric spheres of different radii. (In that sense, a skilled artisanwill understand that a spherical shell is a generalization of an annulusto three dimensions.) A “substantially spherical shell” is defined as anapproximation to the spherical shell in that the bodies limiting thesubstantially spherical shell are substantially spherical orsubstantially spheres—that is, certain dimensional deviations from theideal spherical surface shapes (which are typical during the formationof manufacturing of a sphere or a spherical surface and/or which aredefined by the variation of radii of such spheres within the range of+/−20% of the nominal radii values, preferably within the range of+/−10% of the nominal radii values, even more preferably within therange of +/−5% of the nominal radii values, and most preferably withinthe range of +/−2% of the nominal radii values) are allowed and remainwithin the scope of the claims. In addition or alternatively, andoptionally, the concentricity of such substantially spheres limiting thesubstantially spherical shell may not be perfect, but may be frustratedin that the distance separating the nominal centers of the twosubstantially-spherical bodies limiting the substantially-sphericalshell may be between zero and 20% of the largest value of the radii ofthese two bodies, preferably not exceed 10% of such largest value, morepreferably not exceed 5% of such largest value, and most preferably notexceed 2% of such largest value. In the ideal case, the substantiallyspherical shell has a thickness the value of which remains constant as afunction of angle measured with respect to a chosen axis passing thespatially-coincident centers of the two concentric spheres of differentradii limiting and defining such substantially spherical shell.

Similarly, as used in this application and unless expressly definedotherwise, the terms “lenslet” and “lens element” are defined to referto a single, simple, structurally-indivisible and used singly opticalcomponent bound—in a direction of the axis of such component—by twooptical surfaces that changes the degree of convergence (or divergence,or collimation) of light passing through or traversing such component.In comparison, the terms “lens”, “group of lenses”, “lens system” andsimilar terms are defined to refer to a combination or grouping oflenslets or lens elements. Here, the optical doublet, for example, whichis made up of two simple lenslets or lens elements paired together, isreferred to as a lens and not as a lens element.

The term “image” is generally defined as and refers to an orderedrepresentation of detector output corresponding to spatial positions.For example, a visual image may be formed, in response to a pattern oflight detected by an optical detector, on a display device X such as avideo screen or printer. A “real-time” performance of a system isunderstood as performance that is subject to operational deadlines froma given event to a system's response to that event. For example, areal-time extraction of imaging information (such as a spatialdistribution of optical irradiance, for example) from an opticaldetector of an imaging camera device may be one triggered by the user ora microprocessor programmed to do so and executed simultaneously withand without interruption of a process of optical image acquisitionduring which such spatial distribution has been detected.

The term “object space” is conventionally defined and understood as thespace located outside of the optical imaging system in question and aportion of which—referred to as an object—is imaged through the opticalimaging system onto an image surface (which may substantially coincidewith a surface of tan optical detector). An object point and its image,formed with the use of the optical imaging system, are considered to beoptically-conjugate to one another.

The term “optically-conjugate” and related terms are understood as beingdefined by the principal of optical reversibility (according to whichlight rays will travel along the originating path if the direction ofpropagation of light is reversed). Accordingly, these terms, asreferring to two surfaces, are defined by two surfaces the points ofwhich are imaged one on to another with a given optical system. If anobject is moved to the point occupied by its image, then the movedobject's new image will appear at the point where the object originated.The points that span optically-conjugate surfaces are referred to anddefined as optically-conjugate points.

Now, referring again to FIG. 1 , a nominal mutual orientation (or,nominal orientation, for short) between the substantially-sphericalshell or dome 120 and an optical lens 114 housed within such shell ordome is defined when the shell axis 124 (or axis of the shell passingthrough the center of the substantially-spherical shell) and an opticalaxis 128 of the optical lens 114 substantially coincide (that is, whenthe angle between these two axes is substantially zero). In theorientation illustrated in the example FIG. 1 , the axes 124, 128 areshown inclined with respect to one another.

Depending on the specific implementation, the substantially sphericalsurface(s) of the domes or shell 120 (about 10 mm in outer diameter) canbe diamond-turned or injection-molded and made from transparent plastic,such as Polymethyl methacrylate (PMMA). It can also be made of glass orother appropriate biologically-inert optically-transparent materials. Inone case, it has a thickness of about 0.5 mm.

The portion(s) of the casing 120 not used for viewing of the targetobject space (such as that close to the tether 104) may be made ofother, not necessarily optically-transparent materials, and/or does nothave to be substantially spherical, and only configured to allow formovement or positioning of the components within the casing. To allowvarious components an d sub-system of the camera 120 to be assembledinside the housing shell 120, the shell can be made from two or moreparts that are joined together after the assembly so that the edges fitsnugly and are sealed by water-resistant, clear sealants to secure asmooth surface at appropriate junctions, thereby allowing the assembledembodiments to be fluidly-sealed with the entire surface lending itselfto be cleaned and disinfected using approved cleaning and disinfectingprocedures. There may be incorporated a strain-relief element 130between the tether 104 and the shell 120.

FIG. 2 is a schematic illustration of a related (but notmutually-exclusive with respect to the embodiment 100) embodiment 200 ofa portion of the invention, in which the stands 222 and the base plate222A are shown to be structured a bit differently, while proximal end(s)of the mechanical string(s) or cord(s) 228 is/are affixed to an outersurface of the lens holder 118 (and not to a structural feature insidethe holder 118, as is implied in FIG. 1 ).

Example of an Optical System of an Embodiment of the Imaging Camera

FIGS. 3 through 8 and Table 1 (summarizing an output from the Code Voptical design software) provide illustrations to a non-limiting butspecific example of an optical imaging system 300 utilized in anembodiment of the invention. A person of ordinary skill in the art willappreciate that, while the optical imaging system of the camera at handmay be, under certain circumstances, configured such that only theoptical lens 114 is utilized to form optical image(s) of the targetportion of the object space while the optical properties of the shell120 are not considered in formation of such image(s), in thepractically-preferred configuration the optical (imaging) properties ofthe ever-present optically-transparent shell-shaped capsule should betaken into account as those of a portion of the functional opticalimaging system. It is this preferred example that is considered below.

TABLE 1 RADIUS OF APERTURE ELEMENT CURVATURE DIAMETER NUMBER FRONT BACKTHICKNESS FRONT BACK MATERIAL OBJECT (OBJ) 10.0000     10.0000 AIR140.1046 −5.0000 (310) 5.0000 CX  4.5000 CC 0.5000 9.8000 8.8000 ACRYLIC1.0000 DECENTER(1) 425.9036 −2.5000 (314) 7.1495 CX  1.0273 CC 0.32403.8810 1.9490 NSK16 Schott 0.5148 (318) 1.6779 CX  0.7401 CC 0.15001.8207 1.3530 NLAF2 Schott 0.5617 (322) 1.3853 CX −1.5475 CX 1.64191.3046 0.5378 NBASF64 Schott 0.1570 APERTURE STOP (AS)   0.2776 0.1348(326) 1.3363 CX −2.5708 CX 0.8360 0.4912 0.9771 NFK5 Schott (IMAGEDISTANCE = 0.6864) IMAGE (IMJ) INF   1.5448 NOTES: Positive radiusindicates the center of curvature is to the right; Negative radiusindicates the center of curvature is to the left; Dimensions are givenin millimeters; Thickness is axial distance to next surface; Imagediameter shown above is a paraxial value, it is not a ray traced value;Other glass suppliers can be used if their materials are functionallyequivalent to the extent needed by the design; DECENTERING CONSTANTSDECENTER X Y Z ALPHA BETA GAMMA D(1) 0.0000 0.0000 3.5000 0.0000 0.00000.0000 A decenter defines a new coordinate system (displaced and/orrotated), in which subsequent surfaces are defined. Surfaces following adecenter are aligned on the local mechanical axis (z-axis) of the newcoordinate system. The new mechanical axis remains in use until changedby another decenter. The order in which displacements and tilts areapplied on a given surface is specified using different decenter typesand these generate different new coordinate systems; those used here areexplained below. Alpha, beta, and gamma are in degrees. DECENTERINGCONSTANT KEY: TYPE TRAILING CODE ORDER OF APPLICATION DECENTER DISPLACE(X ,Y, Z) TILT (ALPHA, BETA, GAMMA) REFRACT AT SURFACE THICKNESS TO NEXTSURFACE REFERENCE WAVELENGTH = 525.0 NM SPECTRAL REGION = 450.0-600.0 NMINFINITE CONJUGATES EFL = 0.6061 BFL = 0.6606 FFL = −1.5775 F/NO =4.3708 AT USED CONJUGATES REDUCTION = 0.0720 FINITE F/NO = 4.5005 OBJECTDIST = 10.0000 TOTAL TRACK = 12.5066 IMAGE DIST = 0.6864 OAL = 1.8202PARAXIAL IMAGE HT = 0.6956 IMAGE DIST = 0.7042 SEMI-FIELD ANGLE =88.0000 ENTR PUPIL DIAMETER = 0.1387 DISTANCE = −1.3280 EXIT PUPILDIAMETER = 0.3368 DISTANCE = −0.8115 NOTES: FFL is measured from thefirst surface; BFL is measured from the last surface

As shown in Table 1 and FIG. 3 , numbering of the optical elements andoptical surfaces is specific to this example of the design. Thus, theobject (OBJ) corresponds to the zeroth surface; the optical element 310representing a portion of the shell-like encapsulating element 120 ofFIGS. 1, 2 is bound, along the axis 124, by the surfaces 1 and 2; thefollowing sequence 340 of optical elements 314, 318, 322, and 326defines an embodiment of the optical lens marked as 114 in FIGS. 1, 2 ,with the element 314 axially by surfaces 3 and 4, element 318 axiallylimited with surfaces 5 and 6 (not labelled for simplicity ofillustration), element 322 axially limited with surfaces 7 and 8, andelement 326 axially limited with surfaces 10 and 11 (not labelled). Theaperture stop AS corresponds to surface 9, while the image surface issurface 12. The optical lent 340 and the shell 310 are shown in anominal mutual orientation.

Light within the range of angles of the FOV of the system 300 arrivesfrom the object OBJ to the outer surface 1 of the shell 310, isoptically imaged through the shell 310 and the optical lens 240 (whilepassing through the aperture stop AS) into the surface 12 to form aspatial distribution of light that is optically-conjugate to thedistribution of light at the object—that is, the optical image of theobject. The front group of lenslets of the optical lens 240 is formed bythe elements 214, 218 each of which in this example is a meniscus lenselement, while the optical power of each of the lenslets from the reargroup of lenslets of the optical lens 240 (which rear group is separatedfrom the front group of lenslets by the aperture stop AA) has a signthat is opposite to the sign of an optical power of any of the lenselements from the front group. The aggregate FOV of the lens assembly300 (formed by three meniscus lens elements and two double-convex lenselements in this example) has a semi-angle of 88 degrees and imagingresolution of about 50 μm in a direction transverse to the local axis ofthe lens 240. (The person of skill will appreciate options of re-designof this example to provide for a different FOV the semi-angle of whichgenerally exceeds 80 degrees, but may be smaller that this value isrequired.)

The maximum diametrical extent of the lens system 240 does not exceed 4mm. Material for the lens elements (providing the well-corrected imagingwithin the spectral bandwidth from about 450 nm to about 650 nm) aresummarized in Table 2. The optical detector is configured to acquire animage with image height of at least 1.54 mm. For the purposes of thisdesign, the object space viewed in the FOV of the system 300 wasconsidered to be a spherical surface centered on the axis 128 at locatedat the object distance of about 10 mm.

FIG. 4 illustrates transverse ray aberrations (both in tangential andsagittal planes) representing optical performance of the embodiment 300:the skilled person will readily appreciate that these aberrations aresubstantially below 12 microns for any field up to at least 88 degrees.FIGS. 5, 6, and 7 illustrate the corresponding spot diagrams and theastigmatic field curvature and distortion as a function of field angle.The optical system is characterized by astigmatism that, in either ofsagittal or tangential planes, does not exceed 20 microns at every fieldheight within a field-of-view of the optical system; by the opticaldistortion that does not exceed 10% at every field angle up to 66°; andby the optical distortion that does not exceed 15% at every field angleup to 88°. The spot diagrams boast the rms spot size below about 4.5microns at the full field height (field of 88 degrees) and below 2.5microns at the full file height of up to 18 degrees, and about 2.5microns for imaging the axial portion of the object in the specifiedFOV.

For assessing other types of aberrations, the identification of what ispractically acceptable comes down to the modulated transfer function(MTF) curves. Based on the proposed design and in reference to FIG. 8(that illustrates parameters of the MTF characterizing the operation ofthe embodiment 300 in the visible portion of the spectrum in theaggregate FOV), the ideal solution is substantially close to beingdiffraction-limited (the top curve among the MTF curves). Notably, theperformance of the design on-axis is close to the ideal solution, withsome falloff at the edge of the field—and would be consideredpractically acceptable by a person of ordinary skill in the art invisual and/or photographic optical systems. Specifically, the cut-offfrequency of operation in the visible portion of the spectrum issubstantially above 200 cycles/mm (both for imaging in tangential andsagittal planes) for imaging in either plane at any field up to at least88 degrees. Such consideration, accepted in related art, at least inpart is explained by the specifics of the practical use of the system,where user generally positions the optical system such that the objectof interest is in the center of the field. Based on the satisfyingperformance demonstrated by the MTF curves of FIG. 8 , the proposeddesign is operationally sound at least in the visible portion of theoptical spectrum.

TABLE 2 Refractive Indices for materials of optical elements of Table 1:WAVELENGTHS MATERIAL CODE 600.00 562.50 525.00 487.50 450.00NSK16_SCHOTT 1.619768 1.621829 1.624331 1.627429 1.631356 NFK5_SCHOTT1.487054 1.488449 1.490126 1.492185 1.494774 NLAF2_SCHOTT 1.7429501.746246 1.750303 1.755407 1.761994 NBASF64_SCHOTT 1.702905 1.7064421.710819 1.716362 1.723582 ACRYLIC 1.491227 1.492930 1.495024 1.4976521.501027

The skilled artisan having the advantage of knowing the example ofdesign of the optical system utilized in an embodiment of the invention,will now readily appreciate that the optical system includes an opticallens having an optical axis and a front lens element (having a non-zerooptical power) that faces the encapsulating optically-transparent shell.The front lens has an apex at the optical axis. The optical lens ismounted within the shell such as to be rotatable about an axis ofrotation at a rotation angle that is defined between the shell axis andthe optical axis and that can assume each and every value within a rangefrom at least −90° and +90° in a chosen plane that contains both theshell axis and the optical axis. Preferably, the encapsulating shell isconfigured as a first optical imaging element of the camera itself,dimensioned as a substantially-spherical shell having a shell axis. Inthis example, it is the combination of the substantially-spherical firstoptical imaging element with the optical lens enclosed by such firstoptical imaging element that is required to form, define, and beidentified as the optical imaging system. In the specific examplediscussed above the optical lens has a field-of-view (FOV) with asemi-angle of up to 88° as measured with respect to the optical axis ofthe optical lens, but since a skilled artisan will now recognize how tochange the value of this FOV, there is simply no practical reason topresent an alternative, related example of the optical system.

Example(s) of Optoelectronic and/or Optoelectromechanical Sub-Systems

Now, several related and/or alternative but, neverthelessnon-mutually0exclosure examples of operable cooperation between theoptical system and additional opto-electronic components and a lenshousing structure, which gives rise to an optoelectronic system of anembodiment of the invention, are discussed.

Example A

An example 1000 of the embodiment 100 is schematically illustrated intwo side views of FIGS. 10A and 10B, in which the optical lens 114 andthe shell 120 are shown in their nominal mutual orientations. FIG. 11illustrates the example 1000 without the housing shell 120 inperspective view. The individual elements/lenslets of the lens 114 arehoused in corresponding lens-holder(s) or housing 1004 (corresponding to118 of FIG. 1 and made from, for example, aluminum-alloy) that arestructured to include appropriate apertures and/or spacers and/orspatial extension to block stray light. The components of thelens-holder 1004 can also be made of plastic or other materials. In oneimplementation, the lens 114 and its housing 1004 have an overall lengthof about 5 mm to 6 mm, with an outer diameter of about 4 mm. Imagesensor(s) (optical detector(s), not shown, are mounted on a PrintedCircuit Board (PCB) 1008 that may be attached to the base of the lensholder 1004. In FIGS. 10A, 10B the lead-line from the numeral 1008 pointto both the image sensor PCB enclosure and appropriately-dimensionedslots for electrical members 1012 (for example, wires) leading to thePCB. For illumination, light emitting diodes (LEDs) 1016 are mountedaround the lens 114 and preferably at the front of the lens housing1004. The set of LED sources 1016 are chosen and appropriatelyconfigured to provide preferably spatially-uniformillumination/irradiation of the target object space through the shell120 with white light and/or mono-chromatic light and/or electro-magneticradiation at non-visible wavelengths.

An image sensor or optical detector is, understandably, positionedbehind the lens 114 at the image plane to capture the image through theshell 120 and the optical lens 114. As the embodiment (100, 1000) ispowered externally and image transmitted via the tether 104 without theneed for a battery inside the shell 120, there remains sufficient spaceinside the shell 120 to accommodate an image sensor that is large enoughto capture images with an array of pixels containing pixels in numberscomparable to or greater than that used in traditionally-configuredendoscopes and far greater than that would be possible in wirelesscapsulated imaging cameras. The image sensor (optical detector) ismounted on a PCB 1008 with other electronic components, thereby formingan image sensor PCB module. The detector is preferably about 5 mm in amaximum dimension to facilitate high-resolution imaging and to allow itto be easily accommodated in the shell 120.

In one specific example, there may be—incorporated in the image sensorPCB module—a Mobile Industry Processor Interface (MIPI) to UniversalSerial Bus (USB) converter, a stream encoder electronic circuitry, aclock generator electronic circuitry, a microcontroller, and a variableresistor. MIPI to USB converter circuitry and the microcontroller may beconfigured to convert Camera Serial Interface (CSI) MIPI signals to USBtransmission data. This configuration may facilitate operating thedetection of the camera as a USB camera by operational systems such asWindows or Linux, for example, and load the Human Interface Devices(HID) driver to control and communicate with the camera. Themicrocontroller may be additionally configured or programmed to operatein coordination with the stream encoder and/or clock generatorelectronic circuitries to apply different stream formats based on user'sselection (for example, a Motion-Joint Photographic Expert Group(MJPEG)). A variable resistor may be used to adjust the voltage appliedto the LED sources to adjust the brightness of the LEDs seamlessly. Itis appreciated that, as portion of the present electronics, there may betangible non-transient memory storage with program code stored thereinthat, when utilized, allows the user to select different resolutions forthe video stream and also grab a specific video frame and save it as,for example, a JPEG file.

The camera housing 1004 is held between two stands or arms 1022(corresponding to 122 of FIG. 1 ) that are attached to the base plate(or, base of the camera stand) 1026. The stands are positioned andshaped to allow free movement of the lens housing at least bout the axisof rotation 1028 passing through the stands 1022 and lying in the plane1030 that is substantially perpendicular to the optical axis 128. Thecamera is moveably affixed to the stands 1022 with appropriate axle(shown as 1102 in FIG. 11 ) that facilitates the rotation or tilt of thecamera about or with respect to the axis of rotation 1028 (the Y-axis ofthe local system of coordinates, as illustrated). In one specificexample, the structural cooperation between the lens holder/camerahousing 1004 and the stands 1022 is judiciously configured to allow thecamera to rotate freely on the axis 1028 within the range of tilt orrotation angles of +/−90° with respect to the nominal orientation shownin FIGS. 10A, 10B, 11 , or even within the range of +/−180° with respectto such nominal orientation.

In at least one embodiment, the base plate 1026 may be attached andfixed to the base or lower portion of the capsule shell above and belowto a strain-relief 1040 (corresponding to 130 of FIG. 1 ) that may beadditionally secured to the outer cover or tubing of the flexible tether104 with adhesive such as epoxy 1038, for example. The base plate 1026may be equipped with apertures or openings 1110 (FIG. 11 ) through whichthe electrically-conducting members (shown as electrical wires, in thisnon-limiting example) 1012 and/or traction cords (or strings) 1034 pass.As will be explained below in more detail in reference to FIGS. 12 and13 , the embodiment 100, 1000 is configured to utilize the tractioncords 1034 attached to the lens holder 1004 internally, as well as themotor control unit for changing the spatial orientation of the lens 114with respect to the axis 124 of the embodiment. (While in one embodimentthree traction cords may be used—for example, 1034A, 1034B, and 1034C—inFIGS. 10A, 10B these cords are all denoted s 1034 for the simplicity ofillustration.)

The electric wires that power various components and/or sub-systems ofthe camera such as LEDs, for example, and that transmit the imagesignals emerge from the base 1026 of the capsule housing. The electricalwires exit the housing at its base and may be split in two or morebundles (<1.5 mm in diameter each) that are directed laterally, sidewaysthrough lateral slots below the housing to keep the wires away from thetraction cords 1034 and to facilitate movement of the housing. To thisend, the outer electrically-conducting members/wires 1012 may be passedthrough corresponding apertures or holes the axes of which—in at leastone case—may be angled or tilted with respect to the axis 124 tospatially divert the members 1012 to opposite sides of the capsulehousing, as seen in FIG. 11 , for example. (The holes through which thewires exit the base plate generally have sufficient room to allowmovement of the wires, to reduce the need for the wires to bend andfacilitate the rotational movement discussed elsewhere. Theseholes/slots are structured to divert the electrical wires away from thecenter so that the wires mostly slide in these slots/holes as the lens114 in the holder 1004 is tilted/rotated, while the bending of the wiresis reduced—the bending, otherwise, would produce stiffness andresistance to movement—if the wires are positioned perpendicular to theaxis of rotation. There is also some room around the opening of thewires at the base-plate to allow some lateral movement, again to preventbending of electrical wires and their breaking.) In a related case, thewires 1012 can also be left unsplit/undivided from one another to form asingle wire bundle or column that passes through on one side of thecapsulated embodiment. The intra-capsular wires are dimensioned to belong enough to allow the camera housing 1004 to gently tilt on its axisof rotation 1028 without excessive stress on the wires 1012 andwire-related electrical connections.

In yet another related embodiment (not shown), the wires 1012 exitingthe base 1026 of the housing can be wrapped around the axle 1102 of thehousing structure 1026 at one or both sides so that as the housingrotates on the axle 1102 (about the axis 1028), the wires around theaxle unwind or wind according to the direction of rotation movement tonot subject segment(s) of wire(s) between the axle and the housingstructure to tension or stress that may damage, break or disconnect thewires. In yet another related embodiment, the wires between the PCB andthe tether can be replaced by a flex-circuit that can bend repeatedlywithout breaking.

Non-Limiting Embodiments of Various Controllers for Use with System(s)of Example A

FIG. 12 provides a schematic illustration of a non-limiting example of acontroller 1200 of a hand-held unit (or, remote controller) equippedwith a motor that can be used in conjunction with the embodiment of anoptoelectromechanical system such as that of FIGS. 10A, 10B, 11 toeffectuate the rotation of the camera of the embodiment (and with it,the imaging lens 114) about the axis of rotation 1028 within the boundsof the substantially-spherical optical shell 120 while keeping the shell120 substantially immobilized with respect to the tether 104. Notably,only the mechanical driver portion of the remote controller is shown forsimplicity of illustration, thereby excluding the showing of variouselectrical wiring such as members 1012, for example, as well asmicrocontrollers and/or programmable electronic circuitry that may bearranged to be external to the embodiment 100, 1000. The remotecontroller 1200 depicted in FIG. 12 includes, enclosed in anappropriately-dimensioned housing 1210, a rack-and-pinion mechanism 1220configured to drive/pull the camera-tilting/driving flexible tractioncords 1234(A,B,C) (corresponding to the cords 1034 of FIGS. 10A, 10B)with the use of the DC/stepper motor 1238 in order to transfer thepulling motion applied to the cords to the rotational movement of thelens 114 about the axis of rotation 1028. The force and torque generatedby the motor 1238 is transferred to the rack-and-pinion mechanism 1220with the use of the appropriately-configured bevel-gear mechanism 1232.

In the example of FIG. 12 , shown are three traction cords 1234A, 1234B,and 1234C. In further reference to FIGS. 10A, 10B, and 11 , in the mostgeneral implementation all three cords 1234A, 1234B, 1234C may bedisposed to exit the bounds of the shell 120 of FIGS. 10A, 10B throughindividual ports in the base plate 1026. In this case, the apertures oropenings 1110 for the outermost (lateral) cords 234A, 1234B are angledsuch that the cords are directed towards the outer casing 120 of theimaging camera substantially perpendicularly to the wires 1012 andstands 1022 that support the axle(s) 1102. The central cord 1234 then isplaced to exit the shell 120 through its own, respectively-assignedcentral one of apertures 1110.

Distal ends two of the three cords—cords 1234A and 1234B—are affixed toopposite sides of the housing 1004, perpendicularly to the axis ofrotation 1028, and a pulled through the respectively-correspondingapertures 1110 at the base plate 1026 of the housing 1004. The proximalends of the cords 1234A, 1234B are cooperated with the rack element ofthe rack-and-pinion mechanism 1220 with the use of, in oneimplementation, a fishing-line type fixation element(s) 1242 utilizingset screws (it is understood that a differently configured fixations canbe used as well). Through the mechanism 1220 and the mechanism 1232,these cords 1234A, 1234B are further attached to the motor 1238 (or, ina related embodiment, a hand-dial type of the repositioner placedinstead of the motor 1238; not shown) that in operation provides thetraction needed to move the cords within the tether 104 and hence tiltor rotation the imaging camera of the embodiment 100, 1000 in theangular space denoted as “altitude” in FIG. 1 . In particular, tractionapplied to a chosen one of the lateral cords 1234A, 1234B with the useof the mechanisms 1232, 1220 transfers the torque generated by the motor1238 to the rotational motion of the housing 1004 to tilt the housing1004 (and with—the lens 114) towards and in the direction of such chosencord. An edge of the camera housing 1004 that comes into contact withthe lateral cords 1234A, 1234B (or, the respectively corresponding cordsshown as 1034 in FIGS. 10A, 10B) may be spatially-curved to reducefriction experienced by the cords and the off chance that the cords maywear out during repeated pulling/tilting. As the cords 1234A, 1234B (and1234C, if used) exit the housing of the hand-remote unit, or at pointswhere they change direction, they will pass around rounded surfaces suchas pulleys (not shown), to reduce friction when traction is applied.

A third traction cord, shown as 1234C, may be drawn between the lateralcords 1234A, 1234B and attached at its distal end to the center of thebase 1026 of the camera housing to favor positioning of the camera at a0° tilt, or at the longitudinal axis 124 of the embodiment 100, 1000.While the two lateral cords are connected to a motor 1238 at the remotecontroller 1200, the central cord 1234C maintains tension at asubstantially constant, unchanging level by being attached proximally toa resilient element 1250 (shown as spring) in the housing 1210 of thecontroller 1200. In at least one case, the flexible cords 1234(A,B,C)may be made of materials such as nylon, fluorocarbon, or polyethylene,and dimensioned to be about 0.15 mm in diameter in order to withstandforce/weight of at least 250 g (in a related embodiment—up to 500 g; inyet another implementation—up to 1 kg).

It is appreciated, therefore, that a combination of optoelectronicsystem that includes the imaging camera (providing at least a portion ofthe optical imaging system of an embodiment of the invention) andassociated electronic components and subsystem as discussed in referenceto FIGS. 10A, 10B, 11, together with the mechanical arrangementsdiscussed in reference to FIG. 12 forms an optoelectromechanical systemaccording to one embodiment of the idea of the invention. In suchoptoelectromechanical system, a first string is connected to a firstpoint of the holder of the optical lens of the embodiment and a secondstrings is connected to a second point of the holder of the optical lens(with the first and second points being substantially diametricallyopposed to one another with respect to the optical axis of the opticallens). The first and second strings are drawn through the tether of theembodiment to a remote controller at the second end of the tether, andthe remote controller is configured to have a chosen one from the firstand second strings pulled to tilt the optical lens with respect to theaxis of the substantially spherical shell of the embodiment.

Depending on the specifics of a particular implementation of theoptoelectromechanical system of the invention, at least one of thefollowing conditions may be satisfied: (a) the optoelectromechanicalsystem includes a third string connected to a center of the base portionof the holder of the optical lens and drawn through the tether betweensuch center of the base portion and a resilient element within theremote controller, while the remote controller is configured tostabilize a neutral orientation of the optical lens; (b) the remotecontroller includes a rack-and-pinion mechanism within a housing of theremote controller, such mechanism being configured to pull a chosen oneof the first and second strings; and (c) within the housing of theremote controller, there is a motor and, optionally, a microcontrollerconfigured to govern the motor to operate the rack-and-pinion mechanism.

For completeness of the description of the example, the schematic of apanel 1300 of the remoter controller 1200 is shown in FIG. 13 ,illustrating buttons/key and corresponding insignia on the front portionof the housing 1210. As was already alluded to above, the controller1200 may additionally include a microcontroller (not shown) configuredto facilitate delivery of electrical power and transfer of electricalsignals to and from the embodiment of the optoelectronic systemcontained in the shell 120 through the wiring inside the tether 140,start and/or stop the imaging process, govern the operation of theilluminating light sources (controls 1308A, 1308B) delivered from thewhite or mono-chromatic LEDs 1016 through the optically-transparentshell 120 to the target portion of the object space (e.g., the internalorgan of interest), and/or to format imaging process to acquireindividual snapshots and/or video recordings (see controls 1310), and,for example, govern the movements of the encapsulated imaging camera(controls 1304, 1314).

In further reference to FIG. 12 , while the specific implementation ofthe movement controller illustrated in that Figure is designed to bemotorized, in a related embodiment it may be replaced with a manualdial. As shown, however, the stepmotor 1238 is used to control theposition of the camera head, for example the clockwise rotation of themotor leads to rotation/tilt of the camera head in a clockwise direction(with respect to the chosen reference axis and/or plane), while thecounterclockwise rotation of the motor 1238 causes the camera head torotate/tile in a counterclockwise direction. The stepmotor may bepowered via the USB 3.0 connector; buttons/keys 1314 can be pressed todirect the camera to a desired direction. The adjustor “R” may beassociated with rotating the camera head rotate clockwise, while theadjustor “L” can be wired to rotate camera head rotate counterclockwise.The adjustor “Center” is structured and appropriately wired to returnthe camera to its original, nominal position along the axis 124 of thecapsular shell 120, or 0° in the “altitude” angular space of FIG. 1 .

As far as the process of irradiating the object space with light fromthe light sources 1016 is concerned, the remote controller 1200 may havetwo groups of buttons/keys/adjustors to switch between white andmono-chromatic LEDs, 1016. One group (labelled 1308A) may be used tocontrol the white-light LEDs 1016, while the other (labelled 1308B) maybe used to control the monochromatic LEDs 1016 or alternate source ofelectromagnetic radiation present at the embodiment of the camera. Thebrightness of the LEDs 1016 may be controlled by changing the current tothe LEDs from 0 A to 0.6 A, in one case. The “snapshot” button 130 iswired to grab the current, instantaneous image frame from the overallvideo stream recorded by the camera and to save such frame into thespecified data folder of the tangible storage medium of the embodimentas a JPEG file. The “video” button 1304 and associated portion of theelectronic circuitry of the embodiment of the remote controller 1200 maybe used to record a video of the display by pressing this button.

Non-Limiting Example of a Tether for Use with System(s) of Example A

As a skilled artisan has readily appreciated by now, the cooperationbetween an imaging camera of the system of the invention and the remotecontroller 1200 and/or auxiliary external microcontroller and/orprogrammable electronic circuitry (which, when present, is indicatedwith the arrow in FIG. 1 ) is provided with the use of the tether 104that is devoid of any channel configured to transmit light. To thisend—and in reference to FIG. 14 showing a schematical cross-section ofan embodiment 1400 of the tether 104—once the traction cords1234(A,B,C), for example, exit the shell 120 through the strain reliefelement 130, the cords are individually housed inside respectivelow-friction flexible tubes that facilitate the movement of the cordsalong and inside the tether 104, 1400 to successfully tilt the camera inthe desired direction. The traction cords 1234(A,B,C) in therespectively-corresponding tubings are packaged along-side theelectrical wires 1012 that are housed in their respective insulatingcovers inside the tether 104, 1400. In particular, FIG. 14 illustratestilt-driving cords inside low-friction tubes as 1410, and three shieldeddifferential electrical-member pairs with ground wires as 1420. Numeral1424 denotes the electrical members configured to transfer serial dataand clock (clocking data); numeral 1428 identifies the electricalmembers transferring the LED control signals; numeral 1432 representsthe members configured to represent the power transfer and/or ground;while numeral 1440 identifies the PVC jacket and braid shield, whenpresent.

In one non-limiting example, the outer diameter of an embodiment 1400 ofthe tether 104 may be about 3 mm; the tether is made highly pliable (forexample, of polyurethane or silicone or a similar material that is inaddition fluid resistant) to facilitate swallowing and using of thecapsule 100, 1000 with the tether inside the gastro-intestinal tract.The outer surface of the tether 104 preferably carried markings atregular intervals along the length (for example, every 1 cm and every 5cm) to allow the user/clinician to assess distances from the incisorsand/or the entry point of an organ that is at the moment opticallyinvestigated with the camera of the embodiment, to estimate thedimension(s) of lesions or objects encountered in that organ. The tethercan be made 50 cm to 100 cm in length, in at least one case, or it maybe made to be longer or shorter, depending on the specific application.

Example B

A related embodiment 1500 of the optoelectronic/optoelectromechanicalencapsulated system of the invention (approximately corresponding tothat displayed in FIG. 2 ) is schematically illustrated in FIGS. 15A,15B, 16 . Being generally very similar to that of the embodimentdiscussed above in reference to FIGS. 10A, 10B, 11 , the housingstructure (including at least the lens holder 1504, the stands or arms1022, the axle(s) 1502 defining the axis of rotation 1028 and withrespect to which the lens 114 with the lens holder 1504 (with theassociated enclosed PCB and the image sensor 1508) can be tilted orrotated and that connect the stands 1022 with the lens holder 1504)inside the substantially-spherical shell 120 may nevertheless beconfigured a bit differently from the housing structure of theembodiment 1000 to accommodate the differences in electrical wiring 1512and tilt/driving string 1534 cooperation from those of the embodiment1000.

In particular, the electrical wiring 1512, which power the imagingcamera, LEDs 1016, and that transmit the signal representing an acquiredoptical image(s) through the tether 104, emerge from the tether at base1526 of the housing structure and then may be split in two or morewiring bundles that are optionally directed laterally throughappropriately-dimensioned lateral slots 1530 below the housing to keepthe individual bundles away (spatially separated) from the two cords1534. The wires 1512 can also be configured to form a single column orbundle that passes through on one side of the encapsulatedoptoelectronic system. In any case, the portion of the electrical wiringwithin the shell 120 is long enough to allow the imaging camera togently tilt about the axis 1028 without excessive stress on the wiresand their connections. There are two traction cords 1534 in thisimplementation, that are drawn through respectively-correspondingopenings 1610 in the base plate 1526 of the housing structure (see FIG.16 ). The ends of the cords 1534 are attached to the opposite sides ofthe lens holder 1504 externally, as shown. (In comparison with theembodiment 1000, the third, centrally-located cord is optional and notpresent in the illustrated case but, if present, can be used to helpposition the camera in the forward or 0° position, with its own drivemotor or spring in the hand-control unit, as discussed above inreference to the embodiments 1000, 1200) Just as in the embodiment 100,the flexible cords 1534 can be made of materials such as nylon,fluorocarbon, or polyethylene; be about 0.15 mm in diameter, able towithstand weights to facilitate camera movements; as an example, aflexible cord able to withstand repeated traction weight of about 250 mgor more (preferably, about 0.5 kg or more, and in a related case atleast 250 g) to be used to repeatedly tilt or rotate the camera housingabout the rotation axis 1028 defined by the axles 1602. Two cords areattached to opposite sides of the housing, substantially perpendicularto the axis of rotation and pass-through holes at the base plate towhich the frame is attached. Tension on a lateral cord 1534 through thetether 104 tilts the lens holder 1504 in the direction of such cord.Subsequent tension on the other traction cord 1534 tilts the holder 1504in the opposite direction. The edge of the camera housing/holder 1504that comes into contact with the lateral cords is preferably curved toavoid a sharp edge and thus reduce friction and the chance of the cordsbreaking from repeated tilting (FIGS. 15A, 15B, 16 ).

The light sources 1016 and the imaging modes of operation of theembodiment 1500 are substantially the same as those of the embodiment1000.

In particular, the brightness of the LEDs 1016 may be adjusted with theuse of an appropriate program code with which the microprocessor of theembodiment is loaded, which code continuously samples intensity of anacquired optical image. The program code may be configured toadditionally or in the alternative vary and optimize image contrast. Theillumination delivered from LEDs 1016 through the optically-transparentportions of the substantially-spherical shell 120 can be continuous orpulsed. The modality in which the current through the LEDs 1016 isvaried has the advantage of facilitating the delivery of higher-levelcurrents to the LEDs to produce pulses of illuminating light, while atthe same time avoiding problems of overheating of the embodiment ascompared to the case of using continuous current required for atemporally-continuous illumination of the object space. Pulsed lightingwill also generate a higher intensity of light, thereby enabling theillumination of portions of the object space not reached with a lowerintensity continuous beam. With more than one color of light from theLEDs 1534 (such as white and blue light, for example, both of which canbe alternately pulsed) imaging can be configured in a color-interleavedfashion, for example, when illumination of the object space in only onespecific color selected at a time light can be selected as desired. Withthree (or more) types of LED illumination, such as white, cyan andinfra-red, all three (or more) can be sequentially pulsed to providethree (or more) imaging modalities, as a person of skill in the art willreadily appreciate. Finally, more than one type of illumination can becombined to provide a blended image with, e.g., white and cyanillumination, with infra-red superimposed on it, to provide informationabout tissue characteristics, such as vascularity and metabolism.

Furthermore, just as in the case of the embodiment 1000, whereas whitelight LEDs 1534 may be used for most inspections of biological orinanimate structures of the object space through the shell 120,additional lighting can be used for selective imaging, such as the useof monochromatic light to display high contrast images. As an example,blue or cyan light can be used to provide high contrast images todisplay vasculature as well as changes in cellular lining of abiological organ, such as differences between squamous and columnarmucosa. In addition, wavelengths outside the visible spectrum can beutilized, such as Ultra-Violet or Infra-Red to display images.Electro-magnetic wavelengths may be used to excite molecules in thetissues or materials surrounding the capsule to generate fluorescenceimages that provide additional images or data characteristic of diseasesor conditions such as cancer or inflammation or metaplasia. A pluralityof optical techniques from white light imaging, to monochromatic lightimaging to fluorescence, absorption, and multi-photon imaging may beincorporated into such a tethered capsule, as well as methods used toimage the structure of surrounding materials and tissues, such asultrasound or photo-acoustic imaging.

The schematic of the hand-held remote control unit 1700 of theembodiment 1500 is illustrated in FIG. 17 : it is substantially similarto that of FIG. 12 , with the exception that operation of only two tiltcords (1534A, 1534B) should be governed in the latter case. (If and whenthe optional third cords 1534C is also used, the embodiment of FIG. 12can be employed.) The cords may be passed around curved surfaces orpulleys (not shown) to minimize friction.

The cooperation between an imaging camera of the system 1500 and theremote controller 1700 and/or auxiliary external microcontroller and/orprogrammable electronic circuitry (which, when present, is indicatedwith the arrow in FIG. 1 ) is provided with the use of the tether 104that is devoid of any channel configured to transmit light. To this end,and in reference to FIG. 18 , shown is a schematical cross-section of anembodiment 1800 of the tether 104 that may include an envelope ortubular member 1804 of a metallic braided shield further encased in apoly-vinyl chloride covering 1810. Once the two traction/tilt cords orstrings 1534 (shown as black circles in the central portion of theschematic 1800) exit the shell 120 through the strain relief element130, these cords are individually housed inside respective spiral coils1814 (shown as circular boundaries around the black circles) thatfacilitate the movement of the cords along and inside the tether 1800 tosuccessfully tilt the camera in the desired direction. Each tractioncord exits the camera capsule through separate holes on the base plate1526. The holes may be angled laterally to one another to contain andguide the two cords 1534 near the center of the base plate to enter thetether 1800. The coiled springs can be made of materials such asstainless steel. As an example, a nylon traction cord 0.15 mm indiameter can be encased in a stainless-steel coil of about 0.3 mm innerdiameter, and about 0.5 mm outer diameter, and made from a 0.1 mmstainless-steel wire. The coiled springs allow the tether 1800 to beflexed without the coiled spring lumen collapsing or kinking. The coiledsprings further allow for changes in the lengths of the traction cords1534, and enables traction cords 1534 to move freely with minimalresistance. The coiled springs are preferably placed at the center ofthe tether, and are adjacent to (and/or surrounded by) electrical wires1812 (wires for power, ground, and control signals, 1822 (this oneindicating shielded differential pairs and ground wires for datatransmission) so as to minimize bending or stiffening of the tether 1800when tension is applied to a given traction cord 1534. The metallicbraided shield 1804 is grounded. This avoids electro-magneticinterference with data transfer through the wires in the interior of thecable and minimizes such effects on regional organs of the body. Thecoiled springs 1814 can be grounded at the hand-held control unit 1700.

Example C

FIGS. 19A, 19B illustrate another related embodiment of the system ofthe invention (which may possibly be viewed as a structural blend of theembodiment of FIGS. 10A, 10B and that of FIGS. 15A, 15B), demonstratingthat various elements and components of various related embodiments canbe interchangeable. Here, the electrical wires 1912 operably connectedto the electronics of the camera are shows to be directed laterally toform spiral loop(s) 1912A about the axles (fitting and resting in theopenings 1920 in the stands 1022) before exiting through holes in thebase plate and entering the tether through the straight relief 130. Thespiral loop 1912A allows the camera to tilt repeatedly without breakingthe wires. The loops 1912A may be formed on one or both axles. In thisembodiment, there are shown three traction cords 1934, by analogy withthe embodiment 1000, which pas through the corresponding openings 1938and may be operated with the use of the controller 1200 through thetether configured according to the embodiment 1400, for example. Numeral1940 denotes a base plate attachment to tether with a fitting connectorand adhesive and covered with a strain relief element 130, while numeral1942 denotes slots dimensioned to spatially divert the electrical wiresaway from the axis and to the sides of the embodiment 1900.

FIGS. 20A, 20B schematically (and not necessarily precisely) illustratetwo different positions of a portion of the imaging system of anembodiment of the invention in which corresponding angular orientationsof a portion/lens 114 (with a semi-angle of the corresponding FOVdenoted as A) of the imaging system housed in a lens holder 1004, 1504that is disposed inside the substantially-spherical shell-shaped frontlens element 120 of the overall imaging system differ from one anotheras a result of the operations of the traction cords (1034, 1234, 1534,1934). In particular, FIG. 20A illustrates the embodiment in a nominalangular orientation when the axis 128 of the lens 114 and the axis 124of the shell 120 substantially coincide, while FIG. 20B illustrates theembodiment in the tilted orientation when the angular inclinationbetween the axis of the lens 114 and the axis 124 of the shell 120 isdenoted by angle B. Numeral 2004 denotes the axial and outermost rayssubtending the angle A. Arrow 2010 points towards an embodiment of atether and, through it, to a remote control. Point P is an axial pointof the lens 114 at the top aperture that remains the shortest separationof which from the shell 120 remains substantially constant regardless ofthe variation of the tile angle B within the available range of thealtitude angles (see FIG. 1 ). A skilled artisan will readily appreciatethat, for a fixed design of the optical lens 114 such conditiontranslates to maintaining an apex (an outermost front point) of the lens114 to remain substantially equidistant from the inner surface of theshell 120 within which the rotation of the lens 114, the holder of thelens 114, the sources 1016, and the corresponding optical detector iscarried out simultaneously.

Based on the discussed above mechanical cooperation between the firstshell-like lens element and the optical lens within this first lenselement, the combination of the two is made spatially-repositionable asa whole such that when the first lens element is relocated in space is apre-determined fashion in absence of rotation of the optical lens aboutthe axis of rotation, the optical lens is relocated in space in the samepre-determined fashion.

As follows from the above-provided description of the optical system ofthe invention, for an imaging camera the optical system of which ischaracterized by a (full-angle) FOV of about 180° (as in the examplediscussed above), tilting or rotating of the camera by +/−90° from thenominal mutual orientation between the shell 120 and the optical lens114 allows the user to complete an almost 360 degree view and imaging ofthe object space in a plane containing the axes 124, 128 (and, if therotation of the embodiment about the axis 124 is added by, for example,twisting the tether—an almost spherical view of the object space). Thisdesign allows, as an example, the desired and complete viewing from thepylorus to the gastro-esophageal junction of the stomach, asschematically illustrated in FIGS. 9A, 9B. If the bodily organ or otherobject space being imaged is tilted or bent slightly (as a result of,for example, bending the body of the patient) with respect to the axis124, even the view of a portion of the object space that otherwise maybe obscured by the tether can be successfully imaged. With rotation ofthe lens 114 inside the lens element 120 beyond the +/−90° range, thepossible angular gap that may be present above the camera (as seen inFIGS. 9A, 9B) along the tether and not otherwise covered by the FOV ofthe camera gap above the capsule may be almost completely covered(thereby eliminating the “blind spot” of the camera), except possiblyfor the space blocked from the view by the tether and strain relief (buteven this deficiency may be compensated by slight tilting or bending ofthe organ.

If an image is captured with the camera in the nominal orientation (thatis, looking at the object space along the axis 124, forwardly) and thenthe lens 114 is tilted/rotated repeatedly to the left and right from thenominal orientation while accompanying such rotation with thelongitudinal repositioning of the embodiment along the tubular bodilyorgan, a substantially complete spatially uninterrupted view of thetubular organ may therefore be obtained, including views behind folds orobstacles of the organ that would normally not be seen by a conventionalforward-viewing instrument employed by related art. If necessary,stitching of various images can be performed with software to accountfor overlapping images, to construct a complete, continuous image of atubular organ or pipe or intestine with folds, or cavity or space. As anexample, if the tethered capsule is pulled back along the smallintestine, tilting the lens 114 within the lens element 120 to the leftand right allows viewing of mucosa behind the hundreds of folds (plicaecirculares) in the small intestine that are not well seen by aforward-viewing enteroscope employed in related art.

Alternatively or in addition, when the optical system is configured toprovide an overall semi-angle of the FOV that is smaller than 90°, thetether can be twisted so that the field within the overall, aggregateview of the imaging camera can fill in and cover he gaps in lateral viewalong the azimuth, while traction or release of the tether itself can beused to accomplish complete tubular, co-directional views of a tubularorgan or pipe or intestine, or cavity or space.

The capability to repeatedly direct (back and forth) the imaging cameralongitudinally allows a predetermined portion of the object space (suchas an area of interest of a bodily organ) to be repeatedly imaged,including imaging with alternative modes of illumination discussedabove, or to observe an area that may not have been seen earlier due toa muscular contraction of an organ. Further, by rotating the lens 114 ata slightly different angle, the topography of a lesion can be betterassessed to aid diagnosis, such as when inspecting the outer margins ofan ulcer. In further reference to FIGS. 9A, 9B, raising (repositioning)the capsule of the embodiment along the vertical axis and rotating thelens 114 upwards enables a substantially complete view of the fundus,cardia and gastro-esophageal junction of the stomach. The combination ofviews provide an almost completely spherical view of an organ such asthe stomach.

Collected images can be further displayed and computer-vision processedwith artificial intelligence systems used to provide automated lesionidentification and localization without and within co-directionalimages. The advantage of such a display and relation between images isthat it prevents disorientation of the observer when camera(s) aremoving in varied directions and allows camera movement to be controlledby feedback from the imaged displayed with reference to the selectedreference image. As an example, if the standard image is that of thepylorus of the stomach, other images can be displayed with reference tothe pylorus such that images of the lesser or greater curvature, or theanterior of posterior walls of the body of the stomach will beimmediately known by the physician; this will allow more accurate andcorrect localization of a lesion in the stomach.

It is understood, therefore, that in accordance with the idea of theinvention, an encapsulated and tethered imaging camera and a method foroperating such camera are provided.

Generally, a version of the camera as discussed here contains aninternal (substantially encapsulated in a non-zero optical poweroptically-transparent substantially-spherical shell-like lens element)lens assembly, an image sensor or optical detector, light emittingdiode(s) configured for illumination of the objects space through thisshell-shaped outer casing, which internal lens assembly is positionedsuch that it remains substantially equidistant from the shell at all itspositions for viewing. In one example, the internal lens assemblyincludes four elements providing for a FOV that subtends substantially180° while keeping the spatial resolution of imaging of about 50 μm. Thewider the angle of view, the wider the space that can be imaged at anyone time, however, the angle of view may be varied according to theneeds of an application. The constituent lens elements can be of plasticpolymers or can be made of glass. For use in the esophagus and stomach,the optics are designed to provide optimum imaging performance over therange of distances expected in the esophagus and upper stomach from thesurface of the capsule to 10 cm or further. The focal lengths andfocusing distances can be varied according to the needs of the capsule.In related implementation, the lens can have a fixed focus, or haveauto-focus capability, or may include a liquid lens to enablere-focusing. The lens design understandably accommodates the refractiveindex of the transparent casing of the capsule so that there is no imagedistortion as the internal lens assembly is angularly re-oriented in thealtitude angular space.

A method for using such imaging camera generally includes illuminating atarget portion of the object space through the first optical elementwith light generated by the light sources inside the first opticalelement and forming an optical conjugate of a spatial distribution ofthe light, which has been reflected by the target portion, at theoptical detector by transmitting said light through the optical imagingsystem. A method may also include a step of moving the optical lensinside the substantially-spherical shell of the camera while keeping theshell fixed with respect to the target portion and/or oneof:—repositioning of the substantially-spherical shell with respect tothe target portion while keeping the optical lens immovable within theshell; and—repositioning of the substantially-spherical shell withrespect to the target portion while moving the optical lens inside theshell. Alternatively or in addition, an embodiment of the method mayinclude transferring electrical signals representing said optical imagefrom inside the substantially-spherical shell to electronic circuitrylocated outside the shell along the tether and at least one of:—passingalong the tether an electrical signal that defines a stream format forthe transferring of the optical images, and—with the use of amicrocontroller, adjusting voltage applied to the light sources of theoptical imaging system to vary intensity of light generated by at leastone of said light sources. In substantially any implementation of themethod, at least one of the following optional conditions may besatisfied:—the process of transferring of electrical signals includestransferring electrical signals along an electrically-conducting memberthat passes through an opening formed in a base of a holder of theoptical lens, wherein said opening is dimensioned to not constrain amovement of the member in the opening when a portion of theoptoelectronic system to which the electrical member is connected isbeing tilted or rotated;—said transferring includes transferringelectrical signal along the electrically-conducting member that ispositioned to form a loop or a spiral around an axle of rotation of theoptoelectronic system to reduce bending of said member when the portionof the optoelectronic system to which the electrical member is connectedis being tilted or rotated; and—the opening in the base of a holder ofthe optical lens is dimensioned to divert the electrical memberlaterally away from an axis of the holder to substantially preventbending of the electrical member when the portion of the optoelectronicsystem to which the electrical member is connected is being tilted orrotated. Furthermore, alternatively or in addition, the method for usingthe camera to form an optical image may include pulling at least one ofthe first string and the second string with the use of the remotecontroller to change an angular orientation of the optical lens withrespect to the shell axis. (In at least one case, such pulling includespulling the at least one of the first string and the second string thatis covered with either a corresponding spiral coil or a tubing andlocated in the axial region of the tether to achieve at least one of thefollowing effects: —to reduce a lengthening of the at least one of thefirst string and the second string forced by said pulling; and—to expandand contract about the at least one of the first string and the secondstring to reduce a degree of bending of the at least one of the firststring and the second string when a portion of the optoelectromechanicalsystem to which said at least one of the first string and the secondstring is attached is being tilted or rotated.) In any implementation ofthe method, the following operations can be performed: ceasing thepulling procedure; and manipulating the (optionally present) thirdstring, while no stress is applied to the first string and the secondstring, to return the optical lens of the camera to the nominalorientation.

While specific values chosen for these embodiments may be recited, it isto be understood that, within the scope of the invention, the values ofall of parameters may vary over wide ranges to suit differentapplications.

At least a part of the process of operation of the camera has beendescribed as including a processor (microprocessor, electroniccircuitry) controlled by instructions stored in a memory. The memory maybe random access memory (RAM), read-only memory (ROM), flash memory orany other memory, or combination thereof, suitable for storing controlsoftware or other instructions and data. Those skilled in the art shouldalso readily appreciate that instructions or programs defining thefunctions of the present invention may be delivered to a processor inmany forms, including, but not limited to, information permanentlystored on non-writable storage media (e.g. read-only memory deviceswithin a computer, such as ROM, or devices readable by a computer I/Oattachment, such as CD-ROM or DVD disks), information alterably storedon writable storage media (e.g. floppy disks, removable flash memory andhard drives) or information conveyed to a computer through communicationmedia, including wired or wireless computer networks. In addition, whilethe invention may be embodied in software, the functions necessary toimplement the invention may optionally or alternatively be embodied inpart or in whole using firmware and/or hardware components, such ascombinatorial logic, Application Specific Integrated Circuits (ASICs),Field-Programmable Gate Arrays (FPGAs) or other hardware or somecombination of hardware, software and/or firmware components.

It is appreciated that the discussed opto-electronic imaging system(imaging probe) generally—and whether or not a specific configuration isexpressed in the attached drawings—includes a distal portion in which anopto-electronic circuitry with an embodiment of the optical system ofthe invention is/are disposed, a proximal portion preferably removablyconnected to at least a programmable processor and/or an appropriatedisplay device, as well as the housing or sheath (throughout which theoptical and/or electrical members operably connecting the programmableprocessor with the opto-electronic circuitry.

For the purposes of this disclosure and the appended claims, the use ofthe terms “substantially”, “approximately”, “about” and similar terms inreference to a descriptor of a value, element, property orcharacteristic at hand is intended to emphasize that the value, element,property, or characteristic referred to, while not necessarily beingexactly as stated, would nevertheless be considered, for practicalpurposes, as stated by a person of skill in the art. These terms, asapplied to a specified characteristic or quality descriptor means“mostly”, “mainly”, “considerably”, “by and large”, “essentially”, “togreat or significant extent”, “largely but not necessarily wholly thesame” such as to reasonably denote language of approximation anddescribe the specified characteristic or descriptor so that its scopewould be understood by a person of ordinary skill in the art. In onespecific case, the terms “approximately”, “substantially”, and “about”,when used in reference to a numerical value, represent a range of plusor minus 20% with respect to the specified value, more preferably plusor minus 10%, even more preferably plus or minus 5%, most preferablyplus or minus 2% with respect to the specified value.

The use of these terms in describing a chosen characteristic or conceptneither implies nor provides any basis for indefiniteness and for addinga numerical limitation to the specified characteristic or descriptor. Asunderstood by a skilled artisan, the practical deviation of the exactvalue or characteristic of such value, element, or property from thatstated falls and may vary within a numerical range defined by anexperimental measurement error that is typical when using a measurementmethod accepted in the art for such purposes. Other specific examples ofthe meaning of the terms “substantially”, “about”, and/or“approximately” as applied to different practical situations may havebeen provided elsewhere in this disclosure.

References throughout this specification to “one embodiment,” “anembodiment,” “a related embodiment,” or similar language mean that aparticular feature, structure, or characteristic described in connectionwith the referred to “embodiment” is included in at least one embodimentof the present invention. Thus, appearances of the phrases “in oneembodiment,” “in an embodiment,” and similar language throughout thisspecification may, but do not necessarily, all refer to the sameembodiment. It is to be understood that no portion of disclosure, takenon its own and in possible connection with a figure, is intended toprovide a complete description of all features of the invention.

While the invention is described through the above-described exemplaryembodiments, it will be understood by those of ordinary skill in the artthat modifications to, and variations of, the illustrated embodimentsmay be made without departing from the inventive concepts disclosedherein. The disclosed aspects may be combined in ways not listed above.Accordingly, the invention should not be viewed as being limited to thedisclosed embodiment(s).

What is claimed is:
 1. An imaging camera having an optical field of view(FOV) and comprising: a first lens element having a non-zero opticalpower and defining a volume substantially surrounded by the first lenselement and an aperture configured to provide access to the volume; anoptical lens disposed inside the volume, wherein the FOV is defined onlyby a combination of the first lens element and the optical lens; a lightsource configured inside the volume to illuminate an object spaceoutside the first lens element only through the first lens element; andan optical detector configured inside the volume to acquire light fromthe object space both through the first lens element and through theoptical lens.
 2. An imaging camera according to claim 1, furthercomprising an optical lens holder affixing constituent lens elements ofthe optical lens with respect to one another.
 3. An imaging cameraaccording to claim 2, further comprising a remote controller thatincludes a rack-and-pinion mechanism and that is configured to pull atleast one cord, connecting the remote controller with the optical lensholder, through a tether.
 4. An imaging camera according to claim 3,wherein the remote controller includes a motor and a microcontrollerwithin a housing of the remote controller, the microcontrollerconfigured to govern the motor to operate said rack-and-pinionmechanism.
 5. An imaging camera according to claim 3, wherein the remotecontroller includes a pully and a wheel and is configured to operate amovement of the optical lens by pulling the at least one cord.
 6. Animaging camera according to claim 1, wherein the optical lens holder hasa front portion and a base portion, wherein the front portion carriesthe light source thereon; wherein the base portion is attached to aprinted circuit board carrying electronic circuitry thereon, theelectronic circuitry containing a programmable microprocessor that isconfigured to at least (a) define stream format for transfer of opticalimages, which have been acquired with the imaging camera, outside of thefirst lens element, and (b) to adjust a voltage applied to the lightsource.
 7. An imaging camera according to claim 6, further comprising: afirst cord drawn through the aperture and attached at an end thereof toa first point of the optical lens holder; and a second cord drawnthrough the aperture and connected at an end thereof to a second pointof the optical lens holder; wherein the first cord and the second cordare further drawn to a remote controller, wherein remote controller isstructured to pull a chosen cord from the first and second cord to tiltthe optical lens inside the volume with respect to an axis of the firstlens element.
 8. An imaging camera according to claim 6, comprising atether (8A) that contains an electrically-conducting member drawnthrough the aperture into the volume and electrically connected to thelight source, and (8B) that contains a first cord and an additional corddrawn through the tether and connected to a remote controller that isconfigured to stabilize a nominal orientation of the optical lens withthe use of cords of the imaging camera.
 9. An imaging camera accordingto claim 1, comprising: a plurality of light sources positioned around afront lens element of the optical lens inside the volume in a plane thatis transverse to an optical axis of the optical lens, wherein theoptical detector and the plurality of light sources are spatiallycooperated with the optical lens such as to move in spatial conformitywith the optical lens.
 10. An imaging camera according to claim 9,wherein different light sources of said plurality of light sources areconfigured to generate light in different spectral regions and/orwherein, when the imaging camera further comprises electronic circuitryelectrically cooperated with said plurality of light sources, saidelectronic circuitry being configured to operate said different lightsources in a pulsed regime.
 11. An imaging camera according to claim 1,wherein the optical lens, the light source, and the optical detector aremechanically cooperated with each other with the use of a mechanicalstructure to form a sub-assembly in which mutual spatial positions ofand orientations between the optical lens, the light source, and theoptical detector are maintained unchangeable; wherein the mechanicalstructure is located completely inside the volume; and wherein themechanical structure is configured to change angular orientation of thesub-assembly with respect to the first lens element while maintaining aseparation of an apex of the optical lens from the first lens elementsubstantially constant regardless of the angular orientation.
 12. Animaging camera according to claim 11, configured to have the opticallens robotically moved inside the first lens element.
 13. An imagingcamera according to claim 11, comprising an electrically-conductingmember electrically connected to at least one of the light source andthe optical detector, said electrically-conducting member being drawnthrough the aperture into the volume and through an opening formed in abase of the mechanical structure, wherein at least one of the followingconditions is satisfied: (13A) said opening is dimensioned to notconstrain a movement of the electrically-conducting member in theopening when the mechanical structure is being tilted or rotated in thevolume; (13B) the electrically-conducting member that is positioned toform a loop or a spiral around an axle of rotation of the mechanicalstructure to reduce bending of said electrically-conducting member whenthe mechanical structure is being tilted or rotated in the volume; and(13C) said opening in the base of a holder of the optical lens isdimensioned to divert the electrically-conducting member laterally awayfrom an axis of the mechanical structure to substantially preventbending of the electrically-conducting member when the mechanicalstructure is being tilted or rotated.
 14. An imaging camera according toclaim 11, further comprising a tether containing a first cord extendingtherethrough and housed in a tubing or a spiral coil disposed in anaxial portion of the tether, wherein the first cord is drawn through theaperture and attached at an end thereof to the optical lens holder. 15.An imaging camera according to claim 1, configured to have the opticallens rotate about an axis of rotation such that a distance separatingthe optical lens from a surface of the first lens element remainssubstantially constant for every angle of such rotation, wherein theaxis of rotation passes through the volume.
 16. An imaging cameraaccording to claim 1, wherein the optical lens is configured to berotatable about an axis of rotation at a rotation angle, that is definedbetween an axis of the first lens element and an optical axis of theoptical lens and that can assume each and every value at least within anrange between −90° and +90° in a chosen plane containing both the axisof the first lens element and the optical axis of the optical lens. 17.An imaging camera according to claim 1, wherein said FOV is defined by acombination of (i) three meniscus lens elements, and (ii) two lenselements each of which is bound by two convex surfaces.
 18. An imagingcamera according to claim 1, wherein the optical lens has an opticalaxis and a front lens element that faces the first lens element, andwherein at least one of the following conditions is satisfied: (18A) adistance between an imaging plane of the imaging camera and an apex ofthe front lens element does not exceed 5 mm; (18B) a diameter of thefront lens element does not exceed 4 mm; and (18C) a spatial resolutionof the imaging camera is at least 50 microns.
 19. An imaging cameraaccording to claim 1, wherein said optical lens is characterized byoptical distortion that does not exceed 40% at every semi-field angle upto 66°.
 20. An imaging camera according to claim 1, wherein the aperturesubtends an angle not exceeding 45 degrees as viewed from a center of acurvature of the first lens element.
 21. An imaging camera according toclaim 1, wherein the optical lens satisfies at least one of thefollowing conditions: (21A) the optical lens is characterized byastigmatism that, in either a sagittal plane or a tangential plane, doesnot exceed 25 microns at any field height within a field-of-view of theoptical lens; and (21B) the optical lens is characterized by opticaldistortion that does not exceed 20% at every semi-field angle up to 44°;and (21C) the optical lens is characterized by optical distortion thatdoes not exceed 80% at every semi-field angle up to a maximum semi-fieldangle of the optical lens.
 22. An imaging camera according to claim 1,wherein said imaging camera is devoid of a power source within thevolume.